Mechanism of labor: practice question

A OBG question in the style of the NEET PG paper. Answer it first, then read why the right option is right and why each of the others is wrong.

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OBG · Mechanism of labor

Sample item

Which cardinal movement of labour is a prerequisite for all the others, occurs continuously throughout labour and is most obvious in the second stage?

Original practice item, not a recalled exam question. Nothing here is recorded.

The answer and the reasoning

D. Descent

The fetus must move down the canal for internal rotation, extension and later movements to occur. Engagement happens when the biparietal diameter passes the inlet and often precedes labour in nulliparas.

Option by option

  • A. Extension

    Extension happens at the outlet as the head is born.

  • B. Flexion

    Flexion occurs with resistance during descent.

  • C. Engagement

    Engagement is crossing the inlet.

  • D. Descent (correct)

    Correct. Downward progress underlies the other movements.

Source note: Original NextPrep sample item — pending expert review. This item is original practice material awaiting independent expert review, so confirm important facts in a standard textbook.

More OBG questions

Questions about this OBG question

What is the answer to this OBG question?

The best answer is D, Descent. The fetus must move down the canal for internal rotation, extension and later movements to occur.

Why is "Extension" not the answer?

Extension happens at the outlet as the head is born.

Why is "Flexion" not the answer?

Flexion occurs with resistance during descent.

Why is "Engagement" not the answer?

Engagement is crossing the inlet.

What concept does this question test?

It tests Mechanism of labor in OBG. Engagement happens when the biparietal diameter passes the inlet and often precedes labour in nulliparas.

How hard is this question?

We tag it as an application question: it asks you to use a fact on a patient or a finding. The tag is our own editorial judgement, not an official difficulty rating, so read the reason for every option, not only the answer.

How should I study Mechanism of labor?

Learn management algorithms as steps: PPH, eclampsia, ectopic pregnancy. Then use the flashcards and the other OBG questions on this site to test what stuck.

Is this a real NEET PG question?

No. It is an original practice item (editorial status: sample, version 1). NextPrep does not publish recalled or leaked questions, and independent faculty review of this item has not been completed yet, so confirm important facts in a standard textbook.